Solid electrolytic capacitor with organic semiconductor and method of manufacturing the same

Abstract

Disclosed herein is a solid electrolyte capacitor with organic semiconductor which comprises a capacitor element, a solid electrolyte layer formed by heating and melting TCNQ complex salt, impregnating the TCNQ salt into the capacitor element and thereafter cooling and solidifying the same, a powder coating layer formed to cover an upper portion of the capacitor element through a clearance, and a sealing resin layer covering the powder coating layer for sealing the capacitor element. Since the powder coating layer is formed on the upper portion of the capacitor element through a clearance, it is possible to reduce influence exerted on the element by contraction or expansion caused by thermal stress which is applied in a soldering step. Consequently, it is possible to suppress increase of a leakage current.

What is claimed is: 
     
       1. A solid electrolytic capacitor with organic semiconductor comprising: a capacitor element formed by inserting a separator sheet between an anode foil member being provided with an oxide film on its surface and a cathode foil member and rolling this material;   a solid electrolyte layer formed by heating and melting TCNQ complex salt having electrical conductivity being applicable to an electrolyte for a capacitor, impregnating said TCNQ complex salt into said capacitor element and thereafter cooling and solidifying the same;   a powder coating layer formed to cover an upper portion of said capacitor element; and   a sealing resin layer covering said powder coating layer for sealing said capacitor element.   
     
     
       2. A solid electrolytic capacitor with organic semiconductor in accordance with claim 1, wherein said oxide film of said anode foil member is formed by anodized forming. 
     
     
       3. A solid electrolytic capacitor with organic semiconductor in accordance with claim 1, wherein said oxide film of said anode foil member is formed by anode chemical conversion. 
     
     
       4. A solid electrolytic capacitor with organic semiconductor in accordance with claim 1, wherein said anode foil member and said cathode foil member are prepared from a metal having a valve action. 
     
     
       5. A solid electrolytic capacitor with organic semiconductor in accordance with claim 4, wherein said metal is selected from a group of aluminum, tantalum and niobium. 
     
     
       6. A solid electrolytic capacitor with organic semiconductor in accordance with claim 1, wherein said powder coating layer contains inorganic powder having a melting point of at least 230° C. 
     
     
       7. A solid electrolytic capacitor with organic semiconductor in accordance with claim 6, wherein said inorganic powder is prepared from at least one element selected from a group of activated clay, activated carbon, diatomaceous earth and activated alumina. 
     
     
       8. A solid electrolytic capacitor with organic semiconductor in accordance with claim 1, wherein said powder coating layer contains an inorganic compound. 
     
     
       9. A solid electrolytic capacitor with organic semiconductor in accordance with claim 1, wherein the material for said powder coating layer is selected from a group of epoxy resin, acrylic resin and polyester resin. 
     
     
       10. A solid electrolytic capacitor with organic semiconductor in accordance with claim 1, wherein said TCNQ complex salt forming said solid electrolyte layer is prepared from a mixture of N-phenethyllutidinium.(TCNQ) 2  and N,N-pentamethylene.(lutidinium) 2 .(TCNQ) 4 . 
     
     
       11. A solid electrolytic capacitor with organic semiconductor in accordance with claim 1, wherein said sealing resin layer is made of epoxy resin. 
     
     
       12. A method of manufacturing a solid electrolytic capacitor with organic semiconductor, comprising the steps of: preparing a capacitor element by inserting a separator sheet between an anode foil member and a cathode foil member and rolling this material;   heating and melting TCNQ complex salt having electrical conductivity being applicable to an electrolyte for a capacitor and impregnating the same into said capacitor element;   forming a solid electrolyte layer by cooling and solidifying impregnated said TCNQ complex salt;   forming a powder coating layer covering an upper portion of said capacitor element; and   forming a sealing resin layer covering said powder coating layer for sealing said capacitor element.   
     
     
       13. A method of manufacturing a solid electrolytic capacitor with organic semiconductor in accordance with claim 12, wherein said step of forming a powder coating layer comprises a step of forming said powder coating layer from a powder coating material mixed with inorganic powder or an inorganic compound. 
     
     
       14. A method of manufacturing a solid electrolytic capacitor with organic semiconductor in accordance with claim 13, wherein said inorganic powder is prepared from at least one element selected from a group of activated clay, activated carbon, diatomaceous earth and activated alumina. 
     
     
       15. A method of manufacturing a solid electrolytic capacitor with organic semiconductor in accordance with claim 12, wherein said step of forming a sealing resin layer comprises a step of heating and hardening said sealing resin layer at a temperature lower than the melting temperature of said powder coating material and thereafter heating, melting and hardening said powder coating layer. 
     
     
       16. A method of manufacturing a solid electrolytic capacitor with organic semiconductor in accordance with claim 12, wherein said step of forming a powder coating layer comprises a step of melting said powder coating layer with steam of at least 1 atm.